FAW Rear Axle Housing And Half-Shaft Assembly: A Critical Analysis of Its 8 Core Components

Welcome to this critical technical analysis of the FAW Rear Axle Housing And Half-Shaft Assembly. This is the complete load-bearing and power-delivery system for the rear drive axle of the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is the literal foundation of the “6×4” drive system.

The FAW Rear Axle Housing And Half-Shaft Assembly is a multi-part system consisting of two main functional groups: the ‘Rear axle housing assembly’ (2401010BA6T), which is the structural “skeleton” that holds the differential and bearings, and the ‘Half-Shaft’ assemblies (2403081-A6T & 2403082-A6T) that transmit torque to the wheels.

This in-depth guide is an essential resource for professional driveline technicians, fleet managers, and parts specialists. We will deconstruct the entire FAW Rear Axle Housing And Half-Shaft Assembly into its 8 serviceable components, including the main housing, the individual axle shafts, the magnetic drain plug, and the critical breather valve.

Core Component: The Rear Axle Housing (2401010BA6T)

The heart of the FAW Rear Axle Housing And Half-Shaft Assembly is the ‘Rear axle housing assembly’ (2401010BA6T). This is the main structural component, often called the “banjo” or “carrier.” It is a massive, high-strength casting, typically made of ductile cast iron, designed to handle the entire weight of the tractor’s rear and its cargo, as well as the immense torque loads from the driveline.

This housing performs three critical functions. First, it is the “skeleton” that provides the mounting points for the entire suspension system (leaf springs, air bags). Second, it is the rigid “case” that holds the differential (the ring and pinion gearset) in perfect, precision-machined alignment. Third, it acts as the “axle tubes,” extending outwards to hold the wheel hub bearings.

The housing is also a sealed oil reservoir, holding several gallons of heavy-duty gear oil to lubricate the differential. A crack or bend in this FAW Rear Axle Housing And Half-Shaft Assembly (e.g., from an impact or overloading) is a catastrophic, vehicle-ending failure. Its structural integrity is paramount.

The “Half-Shafts”: Left (2403081-A6T) & Right (2403082-A6T)

The “Half-Shaft” components of the FAW Rear Axle Housing And Half-Shaft Assembly are the ‘Rear axle left half-shaft’ (2403081-A6T) and the ‘Rear axle right half-shaft’ (2403082-A6T). These are the “axles” themselves. They are solid, forged shafts made from an incredibly tough and ductile steel alloy (like 4340 chromoly), designed to twist slightly under extreme torque without breaking.

These are **full-floating** axles. This is a critical design feature for a heavy-duty truck. In this system, the axle shafts “float” inside the housing. Their *only* job is to transmit torque. They do *not* support the weight of the vehicle. The vehicle’s weight is supported by the ‘Rear axle housing assembly’ itself, via the large wheel hub bearings.

This “full-float” design means that if a FAW Rear Axle Housing And Half-Shaft Assembly‘s shaft were to break (a rare but possible event under extreme load), the wheel *will not fall off* the truck. The driver can safely pull over. The shafts are splined on their inner end (to engage with the differential’s “sun” gears) and flanged on their outer end, where they are secured to the wheel hub by the 20 ‘Hex flange bolts’ (Q1851650TF2K).

The reason for a separate “Left” and “Right” half-shaft is simply their length. Due to the central mounting of the differential “pumpkin,” one axle shaft is always slightly longer than the other to reach the corresponding wheel hub. A worn or twisted spline on the FAW Rear Axle Housing And Half-Shaft Assembly is a common failure point that will result in a “clunk” on acceleration and an eventual loss of drive.

Lubrication and Service Logic

The FAW Rear Axle Housing And Half-Shaft Assembly contains several critical service components for its gear oil.

**1. ‘Oil filler plug’ (2401051-A0R):** This is the “fill” and “level check” port. It is located on the side of the differential housing. A technician removes this plug and fills the axle with gear oil until the fluid is level with the bottom of this hole.

**2. ‘Inner hex tapered magnetic screw plug’ (T62104M):** This is the “drain” plug, located at the lowest point of the FAW Rear Axle Housing And Half-Shaft Assembly. Its “magnetic” property is its most important “logic.” The magnet actively traps microscopic metal particles that are a normal byproduct of gear wear. During an oil change, inspecting this plug gives a technician a clear “health report” of the differential. A large amount of “fuzz” is normal, but large “chips” indicate a failing bearing or chipped gear tooth inside the FAW Rear Axle Housing And Half-Shaft Assembly.

**3. ‘Gasket ring’ (CQ72324T5):** This is the single-use “crush washer” for the magnetic drain plug. It must be replaced at every oil change to guarantee a leak-free seal.

The “Breather” Logic (T905)

The ‘Breather plug’ (T905) is one of the most critical, yet simple, components of the FAW Rear Axle Housing And Half-Shaft Assembly. As the differential and its oil heat up during driving, the air inside the ‘Rear axle housing assembly’ expands, building pressure.

This breather plug is a one-way (or filtered) “vent.” It allows this hot, pressurized air to escape. When the axle cools, the air inside contracts, creating a vacuum. The breather allows clean air to be drawn *in*.

A failure of this “logic” is catastrophic. If the ‘Breather plug’ (T905) becomes clogged with mud or dirt, the expanding pressure has nowhere to go. It will force its way out past the weakest points: the axle’s pinion seal and the wheel hub seals, causing a massive oil leak. Conversely, if the axle cools and the clogged breather creates a vacuum, it can *suck in* water and mud during a water crossing, contaminating the oil and destroying the bearings. This tiny plug is essential to the long-term health of the FAW Rear Axle Housing And Half-Shaft Assembly.

The Fastener System: (Q1851650TF2K)

The FAW Rear Axle Housing And Half-Shaft Assembly is held together by the 20 ‘Hex flange bolt, coarse rod (Standard Type)’ (Q1851650TF2K) fasteners. These are the bolts that secure the flanges of the ‘Left’ and ‘Right’ half-shafts to the wheel hubs (10 bolts per side).

These are the final link in the power-delivery chain. They are responsible for transmitting 100% of the engine’s multiplied torque from the axle shaft to the wheel. They are “flange” bolts, which act as an integrated washer to provide a high-clamping force. They are also high-tensile (e.g., Class 10.9) and are often “torque-to-yield” (single-use) fasteners. A loose or broken axle shaft bolt will cause a “clicking” sound as the wheel turns and can lead to a total loss of power on that side of the vehicle. This hardware is a key serviceable part of the FAW Rear Axle Housing And Half-Shaft Assembly.

FAW Rear Axle Housing And Half-Shaft Assembly Parts List

The following table provides the complete, detailed breakdown of all 8 components identified in the ‘Rear Axle Housing and Half-Shaft Logic Assembly’ diagram for the FAW CA4251P66K24T1A3E5 tractor. This FAW Rear Axle Housing And Half-Shaft Assembly is the foundation of the 6×4 drivetrain.

Technical Specifications and Assembly Context

The specifications for the FAW Rear Axle Housing And Half-Shaft Assembly are defined by its function as a heavy-duty, full-floating drive axle. The FAW Rear Axle Housing And Half-Shaft Assembly is the final link in the powertrain.